The present invention relates to repair of radomes, and more particularly, to repair of tapered radar radome structures.
It is known in sophisticated aircraft equipment to have communications devices operating in the very high and ultra high frequency range. Such communications devices often employ an antenna for sending and receiving signals, where it is customary to enclose such antenna in a protective structural body. Such structural body is desired to be transparent to radiation emitted by the antenna, and is commonly referred to as a radome. A radome serves to protect an antenna from the environment as well as providing a selected exterior geometry for the vehicle.
A radome must be designed for efficient energy transmission at the above frequencies and thus is ordinarily made relatively thin, in the order of one-half electrical wavelength in thickness, or possibly a small whole number multiple thereof, as well as being made thin to minimize weight. Furthermore, in the fabrication of radomes, it has been found preferable that a radome be constructed as a single piece employing several layers of structural material in a laminated honeycomb sandwich arrangement. These laminated structures often are assembled out of carefully selected materials so that a preselected gradient of electrical characteristics is obtained throughout the laminated sandwich. The gradient is selected so as to minimize the reflectance of radar from the surface of the radome. It is also known in the art that single piece construction is preferable to the joining together of a multiplicity of pieces of honeycomb because stress concentrations may occur and inherently weak portions of the structure may result.
Nevertheless, once a radome has been manufactured, it is typical that the electrical qualities of the radome, for the particular system to which it is adapted, have sought to have been maximized in addition to obtaining a structurally desirable contour. However, during operation a radome can be damaged by various kinds of flying debris. It is therefore essential to be able to repair an existing damaged radar radome to restore to its prior maximized electrical state and its desired physical contour.
Heretofore, in regard to tapered radar radomes, such damage repair has been considered inadequate in view of the inability to make precision repair. This repair is made difficult in view of the fact that a tapered radome is ordinarily comprised of an outer core ply having an outer fiberglass skin and a first honeycomb core, and an inner core ply having an inner fiberglass skin and a second honeycomb core, where the surfaces of the outer and inner core plies may variably be divergent and convergent with respect to each other. Also, damage repair may be sought to be limited to only one of these core plies, or to merely a skin surface alone, if no core damage has been sustained. This requires yet further precision in repair of a damaged tapered radome.